This invention relates to a bonding method and apparatus for making wiring inside a miniature component More particularly, the present invention relates to a bonding method and apparatus which will be suitable for ball bonding.
The conventional bonding method used for wiring of a semiconductor as typified by so-called "nail head bonding", which is disclosed, for example, in Japanese Patent Laid-Open No. 71642/1986, forms a ball at one of the ends of a thin metal wire, pushes this ball from above and connects it to a substrate by use of a capillary, forms a ball at the other end of the thin wire and connects it in the same way. Japanese Patent Laid-Open No. 173951/1982 discloses a method which is referred to as "wedge bonding".
The prior art technique described above does not take into consideration the shape of the ball after bonding and involves particularly the problem of the shape of the upper part of the ball In other words, the prior art technique has the structure wherein the wire is wired in the vertical direction of the ball after bonding and the shape of the upper part of the ball after bonding is inclined This shape is extremely disadvantageous for bringing a probe pin into contact with the ball from above after bonding in order to check the connection of the bonding portion and the function of the component. Also, the shape described above is disadvantageous, for high reliability connection when ball bonding is made in superposition on the bonding portion.